The invention relates to a method for damage limitation in the event of an offset frontal collision between two motor vehicles, and to a motor vehicle having an apparatus which serves for this purpose. An offset frontal collision is to be understood as a frontal collision in which the vehicles move toward one another with directional vectors which are substantially parallel but laterally offset in relation to one another. The collision zone is therefore only a lateral part of the car in front.
In vehicles, this lateral part in front of the passenger compartment is usually less rigid than the central part in front of the passenger compartment and also absorbs less collision energy, resulting in considerable deformation of the passenger compartment. In particular, there is a risk of the respective wheel entering the passenger space, what is known as an intrusion zone. Furthermore, a particularly dangerous phenomenon also generally occurs in the event of such collisions: even in the event of a relatively small offset, the front wheels of the two vehicles on the collision side interengage with one another. As a result, the wheels are not only subject to particularly severe longitudinal forces which push them toward the passenger space, but the two vehicles are connected to one another in a partially interlocking manner and thus prevent them passing each other by. The kinetic energy of the two vehicles which hit one another eccentrically also causes the two vehicles which then interengage with one another to twist about the vertical axis.
This phenomenon is known in the literature under the term “interengaging”. One countermeasure is known from WO 02/094618 A1—on which the invention is based—in that a signal which signals that a collision is beginning or is soon imminent explosively and irrevocably triggers the steerable front wheels to turn in such a way that the plane of the wheel on the collision side intersects the vertical longitudinal center plane of the vehicle, in front of said vehicle. This “positive” turning of the wheel on the collision side means that said wheel cannot interengage with the wheel on the collision side of the collision partner; the outer face of the rim of the wheel acts rather like a protective shield at which the other vehicle or its wheel on the collision side is deflected away. In order to counteract the impact torque about the yaw axis which is exerted here, the wheel which is not on the collision side is turned in the opposite direction, that is to say likewise inward. The basic outline of the plane of the wheels then forms a V with the apex located in front of the vehicle.
However, this procedure is still not good enough for two reasons:    1. When the collision takes place, an impact torque about the yaw axis acts on the vehicle and threatens to throw it off course.    2. If the collision is prevented at the last moment, that is to say the collision does not take place after all when the wheels are already turned, the vehicle cannot be steered and cannot be driven further because the wheels are irrevocably turned.
The invention is consequently based on the object of providing a remedy in these two regards. The aim is to minimize the impact-induced yaw moment and to be able to drive said vehicle further after a collision which did not take place after all.